e-Salaer is a web-based payroll application for Switzerland and Liechtenstein, offered by the fiduciary firm Presida Treuhand AG of Buchs. Each month the software calculates payslips and the payment file, and at year end it prepares the statutory reports and wage statements, including AHV, UVG and KTG. Nothing needs to be installed: you work in the browser. According to the vendor, there are integrations with Raiffeisen e-banking, Bexio and Smallinvoice. The service is aimed at small and medium-sized employers who want to run their own payroll.
Presida Treuhand AG is based in Switzerland; no parent company is stated. According to its terms and conditions, data is stored in secure data centres in Switzerland. Switzerland is not an EU member but is an EFTA country with a European Commission adequacy decision. There is no self-hosting option: the service runs only at the vendor. No publicly available data processing agreement or GDPR statement for the product was found, so ask the vendor which arrangements apply to your employees' personal data.