# Zyloft – Software Development Studio & Next.js SaaS Starter Kits > Zyloft is a software studio in Germany building Next.js SaaS starter kits, the webhook service HookStead, the invoicing app Zyloft Desk and custom software. Software development & Next.js SaaS starter kits from Germany: Code that ships. Software that stays. Zyloft is an independent software company from Germany. We build our own products: Next.js SaaS starter kits that get developers and founders to launch in days, HookStead for reliable webhooks, and Windows software such as the invoicing app Zyloft Desk. For selected projects, we also take on custom development. ## Next.js SaaS starter kits Production-ready Next.js code with login, payments, email and a bilingual website. Buy once, build your own SaaS on top and launch in days instead of months. - [Cairn](https://zyloft.eu/en/templates/cairn/): Next.js SaaS starter kit for creators. For creators and founders selling digital products, courses or memberships: auth, payments, a shop, emails and a landing page that pops, in English and German. (€199) - [Aven](https://zyloft.eu/en/templates/aven/): Next.js Stripe SaaS boilerplate. For subscription SaaS with a shop: monthly and yearly plans, one-time purchases and shop products with Stripe, plus auth, emails and a sleek dark landing page, in English and German. (€229) - [Fjord](https://zyloft.eu/en/templates/fjord/): Next.js B2B SaaS starter with docs & AI. For B2B SaaS with a calm, Scandinavian-inspired look: landing page, docs portal with an AI assistant, blog, company pages, accounts and Stripe subscriptions. (€229) ## Hosted software for developers Besides starter kits and desktop software, we run our own SaaS. The first one: HookStead, for webhooks you can trust. - [HookStead](https://hookstead.dev/): Webhook monitoring & retries. HookStead sits between your providers and your app: it records every webhook, forwards it with signatures and retries, and shows you exactly what happened at every attempt. ## Windows software - [Zyloft Desk](https://zyloft.eu/en/products/zyloft-desk/): Invoicing software for Windows. Quotes, invoices and e-invoicing for freelancers, the self-employed and small businesses in Germany. Works offline on your own PC, no subscription. (€399) ## Custom software development for selected projects Alongside our products, we take on a small number of projects each year, with the same stack and the same care. - **Set up and adapt:** We install one of our starter kits, adapt it to your brand and features, and take it live with you. - **Custom development:** Web apps with Next.js, mobile apps with React Native and Windows software with C# and .NET. - **Care after launch:** Updates, maintenance and new features, so your product keeps up with new versions and new requirements. ## Guides: invoicing and e-invoicing in Germany - [Invoicing as a Kleinunternehmer in Germany](https://zyloft.eu/en/guides/kleinunternehmer-invoice/): Since 2025, new revenue thresholds and simplified invoicing rules apply to small businesses in Germany. What belongs on your invoice, what doesn't, and where e-invoicing stands. - [Germany's e-invoicing mandate: what freelancers need to know by 2028](https://zyloft.eu/en/guides/e-invoicing-mandate-germany/): Since 1 January 2025, businesses in Germany must be able to receive e-invoices. Transition periods for issuing them run until the end of 2027. An overview for freelancers and small businesses. - [ZUGFeRD or XRechnung? Germany's e-invoice formats explained](https://zyloft.eu/en/guides/zugferd-vs-xrechnung/): Both formats meet the e-invoicing mandate, but they work differently. When to use which, and what to watch out for with ZUGFeRD profiles. - [Invoice requirements in Germany under § 14 UStG: the checklist](https://zyloft.eu/en/guides/invoice-requirements-germany/): The details every invoice in Germany must include, what applies to small-amount invoices and small businesses, and how to number invoices correctly. - [Correcting or cancelling an invoice in Germany: how to do it right](https://zyloft.eu/en/guides/correcting-cancelling-invoices/): A mistake on an invoice? When a correction is enough, when you have to cancel it, and why you must never simply delete or overwrite an invoice. ## Questions, answered ### Who is behind Zyloft? Zyloft is an independent software maker from Germany. We build and sell our own products, which lets us focus on doing a few things really well. ### How do I buy Zyloft software? Once a product is available, its page has a buy button. The checkout is run by Polar, our reseller (Merchant of Record): they take care of payment, VAT and the invoice, and provide your licence key or access. ### Do I need a subscription? We prefer one-time licenses. Where a product needs ongoing work, such as adapting to new tax rules, we offer that as an optional update package, and the software keeps working without it. Each product page states its exact model. ### What happens to my data? As little as possible leaves your device. Zyloft Desk, for example, stores everything in a database on your own PC. Our software contains no advertising or tracking SDKs, and this website sets no cookies. ### Which platforms do you build for? Windows 10 and 11 with C# and .NET, iPhone and Android with React Native, and the web with Next.js. Each product page lists its exact system requirements. ### Can I get an invoice for my business? Yes. Every purchase comes with an invoice that shows VAT. Business customers can enter their VAT ID at checkout. ### Can I get a refund? Yes, within 14 days of your purchase, as long as you haven't used the product yet, for example by accepting the repository invitation, downloading it or activating a licence key. After that, contact us about defects or other problems; your statutory rights always apply. Details are in our refund policy. ### How do I get support? Write to support@zyloft.eu. We answer every message personally. ### How do I hear about new products? Write to support@zyloft.eu and tell us what you're interested in. We'll let you know personally when it's available. ## More pages - [About](https://zyloft.eu/en/about/) - [Contact](https://zyloft.eu/en/contact/) - [Legal notice](https://zyloft.eu/en/legal-notice/) - [Privacy Policy](https://zyloft.eu/en/privacy/) - [Refund policy](https://zyloft.eu/en/refund-policy/) - [Terms](https://zyloft.eu/en/terms/) --- HTML version: https://zyloft.eu/en/ Deutsche Version: https://zyloft.eu/index.md