MCleaner is described as 'iPhone Call and SMS Filter program. With MCleaner you can block incoming calls and SMS messages automatically and protect your privacy. MCleaner allows you to create blacklists, whitelists, profiles and schedules to meet your individual needs'. There are four alternatives to MCleaner for a variety of platforms, including iPhone, Android, Android Tablet, Apple Watch and iPad. The best alternative is Line2. It's not free, so if you're looking for a free alternative, you could try Semisilent or MobileGate.
Line2 is a VoIP phone service that lets you call & text from a separate phone number via WiFi or 3G/4G/LTE. At a small premium, Text & call ANYONE in the US/Canada, forwarding & more. Pick any phone number.
Normally, you have two choices for cellphone calls: be available to called by anybody but potentially interrupted, or be able to focus and be unreachable. Enter SemiSilent with a much-needed third option.