Last updated on 12 May 2026
You often need to project the documents from your smartphone onto a computer in class. Whether it is to quickly share an experience photo, a PDF document or a student production, mobile-computer transfer must be simple and fast. Yet, between missing cables and capricious connections, this operation can quickly become "complex" to say nothing else 😤.
How to easily project the contents of your phone on the video projector of the class? Which solutions allow a Simple document sharing and secure? In this article, I will talk about the best apps to transfer files from smartphone to computer. I will focus on Cool Maze, a tool that I find very useful for the school. Thank you to the reader who gave me this idea and she will recognise herself.
Discover five simple solutions to share documents in class. Compare their functionalities and choose the tool that suits you best.
Table of Contents
Cool Maze: the simple and effective solution to share documents from your smartphone
A solution designed for the class

The Cool Maze Service stands out for its simplicity of use and its absence of technical constraints. No need to create an account or watch ads. In addition, there is no need to install anything on the class computer. A simple web browser is enough to receive your documents.
How does it work?
- On the class computer:
- Open your browser
- Visit coolmaze.io
- A QR code is automatically displayed
- On your smartphone:
- Install the Cool Maze app (available on iOS and Android)
- Select the document to share
- Scan the QR code displayed on the screen
The transfer is instantaneous, and your document is displayed immediately on the class screen.
Examples of use in the classroom include a quick projection of students’ productions, sharing a photo of scientific experience, displaying a correction document or presenting resources found during the course.
GDPR and security
Cool Maze complies particularly well with data protection requirements: it does not carry out any permanent storage, does not collect any personal information and transfers the information directly from one device to another. An essential point for a serene use in school context.
Alternatives to Know
In the face of specific needs or technical constraints, other solutions may be useful. Here is four powerful alternatives to Cool Maze, each with its own strengths.
Zapya: the effective polyglot

Particularly appreciated in international establishments, Zapya offers an interface translated into 6 languages. Its strong point? Transfer without mobile data, convenient in poorly covered areas or when Wi-Fi is unstable.
- Transfer via QR code
- Intuitive interface
- Perfect for large files
- Works offline
LocalSend: the open source solution

For institutions that are aware of free software, LocalSend offers an ethical and transparent alternative for sharing files with your nearby devices. Free, open-source and cross-platform.
- No internet required: Share files directly via Wi-Fi without the need for an internet connection.
- Privacy first: Your files stay local, ensuring the security and confidentiality of your data.
- Cross-platform compatibility: Works perfectly on different devices, making it easy to connect with anyone, anywhere.
Xender: The Champion of Compatibility

The Xender app shines by its versatility and its ability to maintain the original quality of the files.
- Compatible with iOS, Android and PC
- Interface available in 17 languages
- Phone Replicate function useful for backup
- Fast transfer of large files
- Particularly suitable for multimedia files
SendAnywhere: the guardian of confidentiality

For sensitive or confidential documents, SendAnywhere provides an additional level of security.
- Encryption of transfers
- 6-digit code for each shipment
- Support for files up to 10 GB
- Perfect for administrative documents
- Temporary sharing option
Comparative table of solutions
| Criteria | Cool Maze | Zapya | LocalSend | Xender | SendAnywhere |
|---|---|---|---|---|---|
| Installation required | |||||
| On mobile | Yes | Yes | Yes | Yes | Yes |
| On PC | No | Yes | Yes | Optional | No |
| Ease of use | |||||
| Getting started | ★★★★★ | ★★★★☆ | ★★★★☆ | ★★★★☆ | ★★★★☆ |
| Speed of use | ★★★★★ | ★★★★☆ | ★★★★☆ | ★★★★★ | ★★★☆☆ |
| Connectivity | |||||
| Wi-Fi required | Yes | No | No | No | Yes |
| Out of connection | No | Yes | Yes | Yes | No |
| Technical characteristics | |||||
| Max. file size | 30 MB | 1 GB | Unlimited | 10 GB | 10 GB |
| Security and GDPR | |||||
| Encryption | Basic | Basic | Advanced | Basic | Advanced |
| Data retention | Temporary | None | None | None | Temporary |
Sharing documents between mobile and computer should no longer be a technical barrier in the classroom. Cool Maze offers the most direct solution for everyday use, while alternatives can cater to more specific needs. Start by testing Cool Maze: its simplicity will surprise you.
Questions you may be asking yourself
Will the app work on my old smartphone?
Most solutions are compatible with recent versions of Android (5.0+) and iOS (11+). Cool Maze is particularly lightweight and works even on older devices.
What if the institution’s Wi-Fi is blocking transfers?
- Zapya and LocalSend allow Wi-Fi-free transfers
- Check with your digital referent which ports to unlock
- Cool Maze uses generally allowed standard ports
What if the QR code doesn't work?
- Check the brightness of the screen
- Clean the lens of your device
- Get closer to the screen
Do the documents remain on a server?
- Cool Maze: Immediate deletion after transfer
- SendAnywhere: encrypted temporary storage
- Other solutions: direct transfer without storage
How can the confidentiality of sensitive documents be ensured?
Choose SendAnywhere for sensitive documents, with its 6-digit code system and enhanced encryption.
Thank you Fidel for this great article. I admit that when I designed Cool Maze, I hadn’t thought about class. It was a surprise for me to discover its use in schools.
Some technical details: the transfer and fast and seems "direct", but it passes through a server. Thanks to the strong AES end-to-end encryption (advanced encryption), my server cannot decrypt the data that passes through. Works in wifi, or also in 4G. Max size 30MB per file. Available in 5 languages. Also, you can click on the QR code to display it larger, and thus scan from the back of the class.
Hello, Trebleshot is not available on the Playstore or on F-Droid. In any case, not with that name. Any idea?
Good morning.
You're right Trebleshot just disappeared from the radar. Thank you for your vigilance. I just replaced it with another open-source alternative: LocalSend
Hello
I am the teacher who suggested the Cool Maze app to you. I wanted to congratulate Valentin Deleplace for making his app easy to use. In class, I can no longer do without it, which saves time when I want to show a notebook to my entire class.
Thank you Mr Deleplace!
I have just discovered that there is the reverse formula for transferring from a computer to a telephone. Seeing if this can be helpful to … Fidel teachers, I let you consider the question.
Have a good day.
Agnes
Hello, for Cool Maze, we are asked to register with our credit card?? Not very cool, so!!
Hello,
I just tested Cool Maze, it's really great and indeed I see a lot of possible applications in progress.
Thank you for everything you do, I am always looking forward to the Newsletter.
Hello,
The WhatsApp application also allows for the transfer of communications and documents to the PC(s). Very cordially and congratulations Mr. Mavamuel for your work
Hello
Thank you for all the solutions!
I would like to point out the chingview application, which is rather a viewer: it allows you to take photos and display them in real time, and even to modify them. What's more: simplicity of use
https://chingview.fr/
The author is Thomas Castanet, a mathematics colleague, who also created the chingatome platform, a huge library of mathematics exercises for secondary school.