The HTC One M7 might be an old device but that does not mean it can’t enjoy the Android 5.0 Lollipop. A senior developer at XDA has already developed the Liquid Smooth ROM and it contains the Lollipop OS designed specifically for the One M7.
So if you are a One M7 user, we highly recommend you to download the LS ROM and apply it on your device. The LS ROM is free of issues and it offers the ultimate Lollipop experience on the One M7. This is something that HTC won’t be offering to the device due to its age.
Of course, the installation procedure can be really complicated if you are new to some basic mobile programming. Even so, it is not difficult to pull off. All you have to do is download the LS ROM from XDA. There you will find a thoroughly detailed guide to aid you in the updating process.