We see there were several tools supporting SDLC considering the agile methodology
Each has their own specifications and constraints in supporting the processes which may not able to provide/support the complete product mix of the different processes.
Each is specialized for their own
Ex..you may need to support product mix of different process beat Incident management, Service Management, Service catalogue, Change Management, Problem/Issue Management, Knowledge Management, SDLC etc..
When we compare across there were many tools like JIRA, Service Now, Remedy, Trello, Enlighta, Talisma many in line..
On a broader perspective considering the support of product mix and several aspects like some constraints starting with Flexibility, Transparency, Reporting etc..
As per my personal view Service now is bit more flexible in supporting in fulfilment most of the above needs.
Require some insights/inputs/Feedback..