Literally Excel... It is the most customization directly suited to you with the most basic learning
curve. If you understand rows and columns and can type, anyone can do it.
Not knocking fancier app based stuff, but with office 365, excel has an online component or you can use openoffice or google sheets
. All cloud based and all the same basic platform.
Also great for provisioning
, and if you really wanted, not that hard for the same platform (probably not cloud based for this stuff) to do sms/email reminders, pre-emptive scheduling for calendar maintenance
, barcoding for spares, predictive maintenance, etc... sky is the limit honestly depending on the time you want to spend creating your log book and your advanced excel abilities.