[SalesForce] Can a user with a Salesforce Platform license create custom objects

The use case here is that we're working with a customer to implement FinancialForce PSA and configuring approval for a Timecard object via email.

It seems as though I recall we've been able to do email approvals with Salesforce Platform users in the past, because if we shift the user from Salesforce Platform to Salesforce license, then they're able to approve via email.

Salesforce Platform licenses are designed for users who only need access to custom apps, and NOT the standard CRM functionality. Salesforce Platform users DO have access to the "core" Salesforce Standard Objects and functionality, like...

Accounts
Contacts
Reports
Dashboards
Documents
Custom Tabs

So, if a user only needs to access custom Force.com or AppExchange apps, it's OK to assign them a Salesforce Platform license. On the other hand, if a user needs access to any CRM functionality (eg Sales or Service Cloud), they must be assigned a Salesforce license.

and Chatter Only (aka Chatter Plus) Access to Chatter for people in your company without a Salesforce license PLUS access to accounts & contacts. Additional cost. hope you find the differences ..!