Searching has shown that SquaredUp works with NiCE monitoring for DB2 but there is no mention of either direct integration with Notes/Domino or with NiCE for Notes/Domino. Is this available or being considered/developed?
There are various possibilities to integrate Domino with SCOM and hence also with SquaredUp. While I am not aware of WebService / REST API integration, you can write a MP that either works with the Domino SNMP service or the Notes API. For the latter there is also a PowerShell module to make work easier. However there are potentially security concerns that may come up. The NiCE Domino MP uses a Notes Task written in C/C++ which makes uses of the Notes C API. This route is more complex, hence if you need the full feature set its worth considering [Disclaimer: I am working for NiCE]. If you consider using the NiCE Domino MP, I am sure the vendor can also provide a SqUp integration