Probably overkill, but PRTG is an amazing tool. you can define all types of counters. I use is for servers, routers, switches, WAN links, netflow/sflow stats, SNMP, CPU and Bandwidth usage, etc..., but you CAN define custom counters for damn near anything.
It may not be exactly what you're needing, but it's worth looking into. It's by Paeseller, so something German like that.