The new version (v0.95). Even earlier than planned :)

[added] three different types of constraints ( version 0.8 - one type )
[added] flexibility control
[added] increased precision of the cloth structure calculation ( upto 20 iterations per frame. version 0.8 - one iteration)
[added] Frame skipping slider (allows to skip frame updating during calculations)

I know about this problem. I'll try to fix it in the next version.


Update (v0.96):
[added] Lock anchor points checkbox (the problem described above is partially solved)