Both produce a record. They come from different intentions and they produce very different relationships.
Memory is unreliable and separated parents frequently remember the same conversation differently. A written record of what was agreed prevents a large proportion of disputes from starting.
That is a coordination benefit and it is worth having on its own.
When the purpose shifts from remembering what was agreed to assembling proof of the other person's failures.
The activity looks similar. The effect on the relationship is not, and the other parent usually senses it well before it is stated.
A record kept to coordinate reduces conflict. A record kept to win increases it, because the other person can tell.
Documenting: what was agreed, when, what changed, what happened. Neutral, contemporaneous, logistical.
Case-building: annotated, characterised, and focused on failures rather than facts.
Where there is a genuine safety concern, a persistent pattern that needs addressing, or active litigation, documentation matters and an attorney should be directing what you keep.
That is a different situation from ordinary friction, and conflating them is what turns ordinary friction into litigation.
Whether any record can be used in any proceeding is a legal question that depends on jurisdiction, on the rules of evidence, and on the case. No platform can promise it, and any product implying otherwise is overreaching.
What a good record does is help you remember accurately and give your attorney something real to work from.
Would you be comfortable if the other parent saw exactly what you are keeping and why?
If yes, it is documentation. If not, it is worth asking what it is for.