Typlog is using Algolia as the search engine for our Pro users, and there was no search feature for basic and standard plan users. Now, we have added the search feature for all sites. This search feature is pretty simple, it will only match the query of your posts' titles and subtitles.
For theme developers, you can use js-search hook to popup the built-in search overlay:
<input class="js-search" type="text" placeholder="Search..."
{% if features.algolia %}data-id="{{ site.algolia_id }}" data-key="{{ site.algolia_key }}"{% endif %}>