Silverware is an open-source flight controller firmware developed by GitHub user silver13 for the H8 mini, BWhoop B03, Eachine E011, and E011C FCs. It was forked and further refined by GitHub user NotFastEnuf. It gives you acro mode, is optimized for the STM32F0 processor and is very well-tuned for brushed motors (especially the NotFastEnuf fork).
The Boldclash BWhoop B06 is a good entry-level brushless whoop. However, it has a few problems for me. First, the motors are not good. There are reported problems of shaft collets and bushings falling off. Second, the FC has no OSD. Third, I prefer my whoops tiny, and by that I mean 65mm (okay, a smaller version is supposedly out but it’s not yet widely available). So I build a better BWhoop B06.