Hi.
I am an experienced Google Apps Script developer. I have done many projects with GAS: data scrapers, data loggers/archives, dashboards, Form gathering, file maintenance, etc (gmail/ spreadsheet/ form/ webapp interconnections) - stuff the small business usually needs in their everyday workflows. I would be glad to help you with yours Google Apps Script Task.
I worked with number of API services, although streak and toggl not in that list. But upon first look at their API docs it seems that there will be no problems working with them from Google Apps Script