Registerer (c) 2013 Mike Bergmann
https://blog.mdb977.de/easily-counting-bits-for-registers/
Binary download: 
Registerer is a Hex/Bin/Dec converter aiming embedded developers which have to deal with hardware registers a lot. It's developed using the Qt Framework.
License:
Registerer is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version.
Registerer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with Registerer. If not, see http://www.gnu.org/licenses/.
Usage: (is pretty simple)
Enter a number in the number field and press enter. Prefix the number with 0b in case you enter a binary or 0x if you enter a hex number. CTRL-d (or d[isplay] button) will toggle through dec-hex-bin.
You may show a bit position pointer by entering the position into the pos field. CTRL-t (or the t[oggle] button) will toggle the bit at the position pointed by 'Pos'.
Examples:
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Convert binary 10101010 to hex:
Enter 0b10101010 into 'Number' and press CTRL-d twice.
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Create a hex number with bit 31 is one:
Enter 0x0 into 'Number' to indicate you want a hex. Enter 31 into 'Pos' and press CTRL-t (or the t button).
-
Create a binary number with bit 15 is one:
Enter 0b0 into 'Number' to indicate you want a binary. Enter 15 into 'Pos' and press CTRL-t (or the t button).