While it is not open source, you can check out TWRP Manage.
It has proven to be a very good app, and it is what TWRP Coordinator was initially modeled after. It is also updated regularly and a new patch should be coming out soon.
I have looked at TWRP Manager and a few others before. These seem feature rich, free to use and are very tempting to use, however, I am trying to use stickly open source software (minus firmware...until my next phone).
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The amount of personal information the typical smartphone can provide is astronomical. Less scrupulous or diligent developers can and have wrapped up seemingly innocuous apps that siphon off information weather it be intentional or not. I am not trying to be evangelical about open source software but feel that “sunlight is the best disinfectant” and software that runs at such a low level like live recovery backup apps should be analyzed for security, patched and integrated into aftermarket builds if not AOSP itself.
I will admit I have not audited the AOSP code base nor the apps I have downloaded off of F-Droid. I do not have this amount of time or expertise but I am comforatable with communities of users and develoepers being diligent enough to find and correct issues and not leaving it to one person or organization. I know ChainFire does quite a bit of this himself (example being the Pry-fi patch for OmniROM) and do trust his work yet I still use Superuser over SuperSU. This is a little frustrating seeing Superuser is open source but ClockworkMod isn't and vice versa with TWRP and SuperSU.
I want an up to date, sleek, open source Android with all basic functionality or will develop it myself. Unfortunately, the later will take more time as I need to learn Android development.
</diatribe>
Please, no one take offense to what I am saying. This my personal preference and an option I would want others to have available.