Lexo terms of use
This page applies to Lexo (com.lexo.keyboard), published by K4Y Apps. It is not a first-run acceptance gate - it is a published notice of the terms that govern using the app, and downloading or using Lexo constitutes acceptance of them. This is a plain-English summary, not a substitute for legal advice, and it has not been through formal legal review.
1. Acceptance
By downloading, installing, or using Lexo, you agree to these terms. If you do not agree, do not use the app.
2. Licence
Lexo itself is proprietary and closed source. K4Y Apps does not publish Lexo's source code, and these terms grant you no right to copy, modify, redistribute, or reverse-engineer the app beyond what your local law and the Google Play terms already allow.
Lexo is built as a fork of FlorisBoard, which is licensed under the Apache License 2.0. That upstream code remains under Apache-2.0, and the Apache-2.0 licence text ships with the app as that licence requires. Apache-2.0 permits a closed-source derivative, so building on FlorisBoard does not make Lexo open source. The on-device models carry their own separate licences, listed below.
3. On-device models
Lexo runs several machine-learning models entirely on your device for typing prediction, voice dictation, dictation clean-up and the Settings assistant, along with some other Premium features. Each is covered by its own licence, listed below. None of these models, their weights, or your usage of them are sent off-device except as described in the privacy policy. Lexo converts these models to formats that run on a phone (ONNX or GGUF) and quantises them, and where a row says fine-tuned, Lexo has trained it further. The NVIDIA Parakeet models are converted to ONNX for on-device use, and the v3 pack is also quantised to int8.
| Model | Licence | Used for |
|---|---|---|
| SmolLM2-360M (HuggingFaceTB, fine-tuned) | Apache-2.0 | Typing prediction - English |
| Gemma 3 270M (Google, fine-tuned) | Gemma Terms of Use | Typing prediction - Spanish, Portuguese, French, Swedish, German, Polish, Czech, Turkish, and the English "Battery life" option |
| Qwen2.5-0.5B-Instruct (Qwen Team, Alibaba Cloud) | Apache-2.0 | Settings assistant (optional download) |
| NVIDIA Parakeet TDT 0.6B v2 | CC-BY-4.0 | Voice dictation - English |
| NVIDIA Parakeet TDT 0.6B v3 | CC-BY-4.0 | Voice dictation - Spanish, Portuguese, German, French |
| KBLab KB-Whisper Small | Apache-2.0 | Voice dictation - Swedish |
| OpenAI Whisper large-v3 turbo | MIT | Voice dictation - Polish, Czech, Turkish |
| Silero VAD | MIT | Detecting when you are speaking (bundled with the app) |
| ELECTRA-small (Google, fine-tuned) | Apache-2.0 | Dictation clean-up |
| paraphrase-multilingual-MiniLM-L12-v2 (sentence-transformers, fine-tuned) | Apache-2.0 | Dictation clean-up of numbers and formatting (Auto-clean) |
| Helsinki-NLP OPUS-MT, tc-big models | CC-BY-4.0 | Premium features (language pairs among English, Spanish, Portuguese and Swedish) |
| Helsinki-NLP OPUS-MT, other models | Apache-2.0 | Premium features (the remaining language pairs, including French) |
These models run on three open-source runtimes: llama.cpp (MIT) for typing prediction and the assistant, sherpa-onnx (Apache-2.0) and ONNX Runtime (MIT) for voice dictation. The licence notices for these libraries are in the app under Settings, About, Third-party licenses.
4. Gemma terms pass-through
Lexo's typing prediction for Spanish, Portuguese, French, Swedish, German, Polish, Czech and Turkish, and the English "Battery life" option, is powered by models built from Google's Gemma 3 270M. Lexo has modified these files: they are fine-tuned on additional text, their vocabulary is rebuilt around whole words, and they are quantised to 8 bits. Earlier Lexo versions used Gemma 3 1B IT for some of these languages, and the same terms apply to those. Gemma is provided under and subject to the Gemma Terms of Use found at ai.google.dev/gemma/terms.
As a binding provision of these terms of use: your use of the Gemma-powered features in Lexo is subject to the Gemma use restrictions in Section 3.2 of the Gemma Terms of Use, which incorporate by reference the Gemma Prohibited Use Policy. You must not use Lexo's Gemma-powered features for any restricted use set out in that policy, or in violation of applicable law. If you further distribute Lexo, or any derivative of it that includes the Gemma model, this same obligation - that use of the Gemma-powered features is subject to the Gemma use restrictions and the Prohibited Use Policy - passes on to anyone you distribute to.
Our YouTube channel. Lexo publishes videos on YouTube using YouTube API Services. By watching or interacting with our YouTube content you agree to be bound by the YouTube Terms of Service.
5. Disclaimer of warranty; limitation of liability
Lexo is provided "as is," without warranty of any kind, express or implied, including but not limited to warranties of merchantability, fitness for a particular purpose, and non-infringement. To the maximum extent permitted by law, K4Y Apps is not liable for any indirect, incidental, special, or consequential damages arising from your use of the app, including any output produced by the on-device models.
6. Changes to these terms
If we make material changes to these terms, we will update the "last updated" date above. Continued use of the app after any change constitutes acceptance of the updated terms.
7. Contact
Questions or concerns: [email protected].