  Baryon chiral perturbation theory (BChPT), as an effective field theory of
low-energy quantum chromodynamics (QCD), has played and is still playing an
important role in our understanding of non-perturbative strong interaction
phenomena. In the past two decades, inspired by the rapid progress in lattice
QCD simulations and the new experimental campaign to study the strangeness
sector of low-energy QCD, many efforts have been made to develop a fully
covariant BChPT and to test its validity in all scenarios. These new endeavours
have not only deepened our understanding of some long-standing problems, such
as the power-counting-breaking problem and the convergence problem, but also
resulted in theoretical tools that can be confidently applied to make robust
predictions. Particularly, the manifestly covariant BChPT supplemented with the
extended-on-mass-shell (EOMS) renormalization scheme has been shown to satisfy
all analyticity and symmetry constraints and converge relatively faster
compared to its non-relativistic and infrared counterparts. In this article, we
provide a brief review of the fully covariant BChPT and its latest applications
in the $u$, $d$, and $s$ three-flavor sector.
