If you've been around the custom ROM scene for any length of time now you no doubt no who Francisco Franco is. The man behind the famous Franco kernel, which is well known for its consistently excellent battery life and great device performance, has been working behind the scenes on an epic update to his app which gives you full control over the Franco kernel, as well as keeping you up to date with the latest release of the kernel. Franco has been around the Android scene for a couple of years now, and as such his app has seen a number of redesigns and reworkings to match with Google's ever-changing look of Android throughout the years. This latest update is remaking the app into Material Design guidelines from Google's next release of Android, Andoid L, and it looks absolutely gorgeous.
Right now the new version of the app is under beta testing, so as these things go with beta apps you'll need to sign up for the community here first, then opt-in for the Google Play Beta program for the app, and finally download the app itself which will automatically be the beta version once you've signed up through those links. Last but of course not least is the bug tracker where you can report any problems you're having with the app itself, whether it be device specific problems with the app or otherwise.
If you've never used Franco's kernel on a custom ROM this might just be the best time to give it a shot. I've been using the Franco kernel on my OnePlus One for a while now, and it's generally been the best for me in terms of performance and battery life, and Franco is consistently fast at updating it to keep the kernel in line with any major updates Cyanogen or OnePlus releases. Franco kernel is available for a ton of devices too, but of course make sure yours is one of the supported devices before you plunk money down on the app!