For those have a 32bit devuce but not root and dont have pc to Sign the apk, Here's how you do it too simple
Step 1: Download Apk-Signer on play store the icon is like a gear titled Apk-signer
Step 2: Install and open
Step 3: After you open, you can see at the bottom right there's a 2 option, First is live sign and Seconf is just sign a file, click the 2nd option and choose the file and sign it
Step 4: Wait and Ta Da, You're done.
THIS IS ONLY WHO DONT HAVE ROOT AND THERE DEVICE IS 32 BIT AND DONT HAVE A LAPTOP OR C TO SIGN APK.
Hope this helps