Mobian is described as 'open-source project aimed at bringing Debian GNU/Linux to mobile devices'. There are more than 25 alternatives to Mobian for a variety of platforms, including Android, Linux, Android Tablet, Self-Hosted solutions and VMware Workstation. The best alternative is LineageOS, which is both free and Open Source. Other great apps like Mobian are Android (Free, Open Source), Ubuntu Touch (Free, Open Source), Android-x86 (Free, Open Source) and /e/ (Free, Open Source).
Project Sandcastle: Android for the iPhone Where sandboxes set limits and boundaries, sandcastles provide an opportunity to create something new from the limitless bounds of your imagination. Project Sandcastle is about building something new on the silicon of your hardware.