diff --git a/app/base.go b/app/base.go
index 4b15fa070c..216a472c36 100644
--- a/app/base.go
+++ b/app/base.go
@@ -224,22 +224,11 @@ func (app *BaseApp) Query(reqQuery abci.RequestQuery) (resQuery abci.ResponseQue
 
 // Commit implements abci.Application
 func (app *BaseApp) Commit() (res abci.Result) {
-	/*
-		hash, err := app.state.Commit(app.height)
-		if err != nil {
-			// die if we can't commit, not to recover
-			panic(err)
-		}
-		app.logger.Debug("Commit synced",
-			"height", app.height,
-			"hash", fmt.Sprintf("%X", hash),
-		)
-
-		if app.state.Size() == 0 {
-			return abci.NewResultOK(nil, "Empty hash for empty tree")
-		}
-		return abci.NewResultOK(hash, "")
-	*/
+	commitID := app.store.Commit()
+	app.logger.Debug("Commit synced",
+		"commit", commitID,
+	)
+	return abci.NewResultOK(hash, "")
 }
 
 // InitChain - ABCI
@@ -253,7 +242,7 @@ func (app *BaseApp) BeginBlock(req abci.RequestBeginBlock) {
 // EndBlock - ABCI
 // Returns a list of all validator changes made in this block
 func (app *BaseApp) EndBlock(height uint64) (res abci.ResponseEndBlock) {
-	// TODO: Compress duplicates
+	// XXX Update to res.Updates.
 	res.Diffs = app.valSetDiff
 	app.valSetDiff = nil
 	return
diff --git a/app/doc.go b/app/doc.go
index c81e394320..c207ff31d6 100644
--- a/app/doc.go
+++ b/app/doc.go
@@ -1,9 +1,11 @@
 /*
 Package app contains data structures that provide basic data storage
-functionality and act as a bridge between the ABCI interface and the internal
-SDK representations.
+functionality and act as a bridge between the ABCI interface and the SDK
+abstractions.
 
-BaseApp has no state except the MultiStore you provide upon init.  You must
-also provide a Handler and a TxParser.
+BaseApp has no state except the CommitMultiStore you provide upon init.  You must
+also provide a Handler.
+
+Transaction parsing is typically handled by the first Decorator.
 */
 package app
diff --git a/app/init.go b/app/init.go
deleted file mode 100644
index f7b71d2f56..0000000000
--- a/app/init.go
+++ /dev/null
@@ -1,65 +0,0 @@
-package app
-
-import (
-	"fmt"
-
-	abci "github.com/tendermint/abci/types"
-
-	sdk "github.com/cosmos/cosmos-sdk"
-)
-
-// InitApp - The ABCI application with initialization hooks
-type InitApp struct {
-	*BaseApp
-	initState sdk.InitStater
-	initVals  sdk.InitValidator
-}
-
-var _ abci.Application = &InitApp{}
-
-// NewInitApp extends a BaseApp with initialization callbacks,
-// which it binds to the proper abci calls
-func NewInitApp(base *BaseApp, initState sdk.InitStater,
-	initVals sdk.InitValidator) *InitApp {
-
-	return &InitApp{
-		BaseApp:   base,
-		initState: initState,
-		initVals:  initVals,
-	}
-}
-
-// InitState - used to setup state (was SetOption)
-// to be call from setting up the genesis file
-func (app *InitApp) InitState(module, key, value string) error {
-	state := app.Append()
-	logger := app.Logger().With("module", module, "key", key)
-
-	if module == sdk.ModuleNameBase {
-		if key == sdk.ChainKey {
-			app.info.SetChainID(state, value)
-			return nil
-		}
-		logger.Error("Invalid genesis option")
-		return fmt.Errorf("Unknown base option: %s", key)
-	}
-
-	log, err := app.initState.InitState(logger, state, module, key, value)
-	if err != nil {
-		logger.Error("Invalid genesis option", "err", err)
-	} else {
-		logger.Info(log)
-	}
-	return err
-}
-
-// InitChain - ABCI - sets the initial validators
-func (app *InitApp) InitChain(req abci.RequestInitChain) {
-	// return early if no InitValidator registered
-	if app.initVals == nil {
-		return
-	}
-
-	logger, store := app.Logger(), app.Append()
-	app.initVals.InitValidators(logger, store, req.Validators)
-}
diff --git a/store/types.go b/store/types.go
index 51582f8bb9..556320f556 100644
--- a/store/types.go
+++ b/store/types.go
@@ -153,6 +153,10 @@ func (cid CommitID) IsZero() bool {
 	return cid.Version == 0 && len(cid.Hash) == 0
 }
 
+func (cid CommitID) String() string {
+	return fmt.Spritnf("CommitID{%v:%X}", cid.Hash, cid.Version)
+}
+
 // bytes.Compare but bounded on both sides by nil.
 // both (k1, nil) and (nil, k2) return -1
 func keyCompare(k1, k2 []byte) int {