There are so many customer ROMs for the HTC One (M8) that it’s often hard to choose which ROM you want to run. Nandroid backups come in quite handy if you’re constantly switching ROMs, but things have just gotten a lot easier thanks to boringalex’s unofficial port of MultiROM manager for the HTC One (M8). MultiROM is a utility which allows you to install multiple ROMs on your phone without needing to flash theme every time you want to switch. With MultiROm installed you can flash as many custom ROMs onto your HTC one (M8) as you want and choose which one you want to use simply by restarting your phone.
MultiROM for the HTC One (M8) has only been available for about a week, but it sounds like it’s pretty stable already. If you consider yourself a frequent flasher, MultiROM will definitely make your life a little easier. Give MultiROM a try and don’t forget to let us know which custom ROM you use the most on your HTC One (M8)
Source: XDA-Developers