I'm just checking in to see if you had a chance to read my last email.
If you're open for a phone/video call on [[day proposed]], let me know!
I hope this email finds you well. I was [[whatever action you were doing that brought them to mind]] this week and you came to mind. Just thought I'd check in and see how things are going. I see that [[check up on their site to see what's new and mention it]]. Looks like you're [[action implied by your observation]]—very exciting!
Hope all is well,