You can try to install Xmrig for Android from F-Droid.org (previously installing F-droid), but if you cannot believe that source, compile from sources with termux.
i used this simple and exact instruction: https://gist.github.com/BenjaminWegener/5b9f042255e53addf34744bf5bb2144c
1. Install Termux
Find Termux in Play Store and update it. You can also need to change mirror due to error 403. Run in termux:
2. Install dependencies
apt install git
apt install wget
apt install proot
pkg install cmake
There can be other dependencies, but need to remove some if termux cannot find:
pkg install cmake git libuv* openssl-dev unstable-repo -y
pkg install libmicrohttpd-dev -y
3. Download Xmrig from git and compile
You need to use flag -DWITH_HWLOC because it often causes the error.
git clone https://github.com/xmrig/xmrig.git
cd xmrig && mkdir build && cd build
cmake -DWITH_HWLOC=OFF ..
cp xmrig ..
4. Now you can choose pool and run Xmrig with your rewards address
I use lightweight MyMonero wallet (but it shares your keys with remote server), also I use Monero in Atomic for Android (it is non-custodial).
I choose pool minexmr.com and I use Atomix wallet address here:
./xmrig -o pool.minexmr.com:4444 -u 44vPPReFYh3Mhg2Ax6kY6cXMRqzpgkEz43UukgX14JsuK8VcdHZ7mdwb5T3s5DSPWVYdjN4ys3ftMSQoGXdtQ4bbNqMau1B
5. Check your balance in mining pool
Go to your mining pool dashborad, for example https://minexmr.com/dashboard and paste your rewards address
6. Set Termux use battery without limits
Om Android go to Settings -> Applications -> All Apps -> Termux
and give it all necessary permissions you can find: use battery without limit, work in background.
7. Get a reward
With minexmr.com you can get a reward from 0.5 XMR. There are other pools with less threshold.
You also can run Xmrig for Solo mining, but I think on weak devices it will not give anything.
I have hashrate 184 H/s on Lenovo Tab M10 HD that is extremely low.
Connect our community in Reddit
If you luck to find a block, share XMR with me:
Change Termux repository mirror:
Android Xmrig install: https://gist.github.com/BenjaminWegener/5b9f042255e53addf34744bf5bb2144c
Install Xmrig on Termux: https://gist.github.com/2niuhe/f9c0a1168ebc02bd0b89ffdb7ed21f6c
Xmrig for Android F-Droid: https://github-wiki-see.page/m/termux/termux-packages/wiki/Mirrors