Shopping for apps for client management produces two kinds of answer and they are not really competing. One kind tries to cover the whole relationship adequately. The other does a single job well and expects to sit beside others. Practices usually end up with a mixture and then discover the cost was never the licences, it was the joins: the same client existing in several places, and somebody keeping them in step. Deciding deliberately how many joins you are willing to own is the whole of this decision.
Count the joins, not the apps
Two apps that never need to know about each other cost nothing to run together. Two apps that both hold your client list cost you forever, because the lists diverge and somebody reconciles them. So the question is not how many apps you have, it is how many of them think they own the client. The answer should be one, and everything else should either read from it or not care.
Choose the one that owns the client first
Decide which app is the master record of who your clients are before you add anything else, and pick it for that job rather than for a feature you liked. Everything afterwards is judged on whether it can take clients from the master rather than keeping its own. This single decision, made early, prevents the most expensive and most common mess in small practice software.
When several specialist apps genuinely win
When one part of your work is unusual enough that a general product does it badly, and when somebody in the practice is willing to own the join. Scheduling in some trades, document assembly in others, sector specific compliance workflows. In those cases the specialist app is worth the join, provided it takes its client list from the master and does not invite you to type clients into it.
Questions people ask about apps for client management
How many apps should a small practice run?
As few as cover the work, with exactly one owning the client list. The number matters less than that rule, which is what keeps the client list trustworthy.
Do integrations solve the join problem?
They reduce it. They do not remove it, because integrations break quietly when either side changes, and somebody has to notice. Fewer joins is still better than well built ones.
What if two apps both insist on owning clients?
Pick one as master and enter clients only there, even if the other allows it. Discipline about where a client is created is worth more than any synchronisation feature.