As @o_e_l_e_o said, Aegis is great 2FA software. But if you're still looking for option, you could check andOTP (https://github.com/andOTP/andOTP) which is slightly more popular option and have few different feature (such as encrypt with PIN).
Well, you set pin instead of words in password field and same function in Aegis
Actually it's good point, although Aegis will spawn QWERTY virtual keyboard rather than numeric virtual keyboard. Should've mentioned there's backup option using OpenPGP instead .
There is setting for pin keyboard if you have numeric password