One-shot launches where timing and preparation decide the outcome. There are 85 in this list, 78 of them free or with a free tier. Every entry shows what it costs, how much work it takes, and links straight to the submission page.
Submit your tool as a genuine indie product and complete the requested launch information.
Submit your real release to the free weekly launch queue.
Submit product if launch flow exists.
Run a crowdfunding or pre-order campaign and link your site from the campaign page.
Launch a campaign for a hardware, creative or game project and link your site from the creator profile.