You can download the M-Tool app for free in the Google Play store and and in the Apple store.
You can download the manual for M-Tool here.
Want to use M-Tool on your desktop? Install an emulator (e.g. Bluestacks) on your computer and install M-Tool in the emulator.
The data generated with M-Tool can be downloaded to the local device only. No third parties (nor the creators) have access to this data.