You can install jailbreak ipa apps through Cydia Impactor. Just drag the files onto the application. Enter your apple id to sign the ipa app, and it will download onto your idevice. Download Cydia Impactor here: http://www.cydiaimpactor.com/ Make sure itunes is installed on your computer. If you don't have iTunes, you can install the latest version here: http://www.apple.com/itunes/download/
Upoad other Apps
To install other ipa apps, you can install them via, http://www.diawi.com Just upload the ipa to the website on your computer, then scan the QR code, or email the link to yourself and download the app. You can also upload it using: Mac and Windows: http://www.i-funbox.com/ Mac Version: https://itools-for-mac.en.softonic.com/mac Windows Version: https://itools-for-windows.en.softonic.com/
Upload ipa Apps to iDevice no computer no jailbreak.